La Niña conditions continue over the tropical Pacific Ocean. The majority of climate models surveyed by the Bureau suggest this La Niña may be close to its peak, with a gradual decline expected over the remainder of the austral summer and early autumn.

Climate indicators of ENSO continue to exceed La Niña thresholds. Despite some cooling (i.e. strengthening of the La Niña pattern) at the surface of the tropical Pacific over the past fortnight, sea surface temperatures remain less extreme (i.e., warmer) than at the same time in 2010-11. Atmospheric indicators of La Niña also strengthened slightly over the last fortnight, with the Southern Oscillation Index (SOI) monthly December value of +23 being the highest value since the breakdown of the 2010-11 event in autumn 2011. The effects of this La Niña can be seen in Australia, with much of the country receiving above average rainfall since October.

La Niña periods are usually, but not always, associated with above normal rainfall during the second half of the year and summer across large parts of Australia, particularly the eastern and northern regions. Daytime temperatures are typically cooler than average, while there is an increased tropical cyclone risk for northern Australia during the cyclone season (November to April), peaking in February and March. For the cyclone season so far, three tropical cyclones have occurred in the Australian region. For detailed rainfall and temperature outlooks, please see: www.bom.gov.au/climate/ahead.

La Nina is at its peak according to the Australia Bureau of Meteorology.